Russian doping whistle-blower Yulia Stepanova said she and her husband fear for their lives after an attempt was made to hack her World Anti-Doping Agency records.

Stepanova, who with her husband, Vitaly Stepanov, helped expose Russia's state-sponsored doping program, has been living in hiding in the United States since the scandal erupted last year.

The 800-meter runner told reporters on August 15 that she and her husband have fresh concerns about their safety following the attempt to find her location by unknown hackers, and they decided to move after the incident.

"If something happens to us, you should know that it is not an accident," Stepanova said.

Her warning comes six months after two former officials with Russia's Anti-Doping Agency died suddenly in February.

Stepanova, who had hoped to compete in Rio as an independent athlete only to be barred by the International Olympic Committee, said she believes doping has been widespread at the Olympics, despite the committee's purported crackdown this year.

"I am certain there are a number of athletes taking part in the Olympic Games who have in preparation used [performance enhancing drugs]. Doping is not only a problem in Russia," Stepanova said.